style: 移除各页面冗余的页面画布和行高样式，统一全局样式管理

1.  移除了20+个页面内单独编写的app-main背景覆盖和行高样式代码
2.  仅保留学生首页的padding和margin清零调整，背景渐变由student-training.scss统一管理
3.  简化代码结构，将页面样式统一收敛到全局配置，减少重复代码

src/assets/styles/student-training.scss

@@ -85,7 +85,8 @@
  * layout's older black gradient as a vertical block beside the sidebar.
  */
 #app .studentLayout .app-main:has(.student-training-shell),
-#app .teacherLayout .app-main:has(.student-training-shell) {
+#app .teacherLayout .app-main:has(.student-training-shell),
+#app .studentLayout .app-main:has(.student-home) {
   background: linear-gradient(135deg, #f5f8fc 0%, #eaf2fb 52%, #f3f8ff 100%) !important;
 }
 

src/views/analysis-of-students/analysis.vue

@@ -337,16 +337,3 @@ onMounted(() => {
   }
 }
 </style>
-
-<style lang="scss">
-/* 非 scoped：覆盖祖先 app-main 画布（浅蓝渐变），本页纯白 */
-#app .studentLayout .app-main:has(.stu-analysis-page),
-#app .teacherLayout .app-main:has(.stu-analysis-page) {
-  background: #ffffff !important;
-}
-
-#app .studentLayout .app-main:has(.stu-analysis-page) .stu-analysis-page,
-#app .teacherLayout .app-main:has(.stu-analysis-page) .stu-analysis-page {
-  line-height: 1.55 !important;
-}
-</style>

src/views/analysis-of-students/dialogue.vue

@@ -673,11 +673,3 @@ const exportData = () => {
   }
 }
 </style>
-
-<style lang="scss">
-/* 非 scoped：覆盖祖先 app-main 浅蓝渐变画布，本页纯白 */
-#app .studentLayout .app-main:has(.ai-dialogue-page),
-#app .teacherLayout .app-main:has(.ai-dialogue-page) {
-  background: #ffffff !important;
-}
-</style>

src/views/assessment/diagnosis.vue

@@ -1079,14 +1079,6 @@ button.is-disabled {
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.diagnosis-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.diagnosis-page) .diagnosis-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.diagnosis-page) .step-indicator {
   display: flex !important;

src/views/assessment/optimization.vue

@@ -1102,14 +1102,6 @@ button:disabled {
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.optimization-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.optimization-page) .optimization-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.optimization-page) .step-indicator {
   display: flex !important;

src/views/channel/supplier.vue

@@ -955,14 +955,6 @@ onMounted(async () => {
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.supplier-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.supplier-page) .supplier-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.supplier-page) .step-indicator {
   display: flex !important;

src/views/demand/business-feasibility.vue

@@ -1046,15 +1046,6 @@ th:last-child, td:last-child { border-right: 0; }
 </style>
 
 <style lang="scss">
-/* 画布背景：纯白，去旧浅蓝渐变 */
-#app .studentLayout section.app-main:has(.feasibility-page) {
-  background: #ffffff !important;
-}
-
-#app .studentLayout section.app-main:has(.feasibility-page) .feasibility-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风（foundation 同款） ===== */
 #app .studentLayout section.app-main:has(.feasibility-page) .step-indicator {
   display: flex !important;

src/views/demand/competitive-environment-analysis.vue

@@ -654,14 +654,6 @@ function exportOutcome() { const blob = new Blob([JSON.stringify(buildDraft(), n
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.competitive-analysis-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.competitive-analysis-page) .competitive-analysis-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.competitive-analysis-page) .step-indicator {
   display: flex !important;

src/views/demand/consumer-behavior.vue

@@ -1762,11 +1762,6 @@ function downloadSurveyReportTemplate() {
 </style>
 
 <style lang="scss">
-/* === 画布背景 === */
-#app .studentLayout section.app-main:has(.consumer-behavior-page) {
-  background: #ffffff !important;
-}
-
 /* === 步骤导航：按钮切换风（foundation 同款） === */
 #app .studentLayout section.app-main:has(.consumer-behavior-page) .step-indicator {
   display: flex !important;

src/views/demand/consumer-scenario.vue

@@ -1669,14 +1669,6 @@ function exportOutcome() {
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.consumer-scenario-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.consumer-scenario-page) .consumer-scenario-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.consumer-scenario-page) .step-indicator {
   display: flex !important;

src/views/demand/feature-conversion.vue

@@ -1375,14 +1375,6 @@ function exportOutcome() {
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.feature-conversion-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.feature-conversion-page) .feature-conversion-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.feature-conversion-page) .step-indicator {
   display: flex !important;

src/views/demand/industry-demand-analysis.vue

@@ -666,14 +666,6 @@ function exportOutcome() { const blob = new Blob([JSON.stringify(buildDraft(), n
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.industry-pest-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.industry-pest-page) .industry-pest-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.industry-pest-page) .step-indicator {
   display: flex !important;

src/views/demand/people.vue

@@ -1942,11 +1942,6 @@ function exportOutcome() {
  * 带 !important 锁定浅蓝，必须在页面非 scoped 块中覆盖）
  * ========================================================== -->
 <style lang="scss">
-/* 画布：纯白，去渐变 */
-#app .studentLayout section.app-main:has(.target-profile-page) {
-  background: #ffffff !important;
-}
-
 /* ===== 步骤导航：按钮切换风（foundation 同款） ===== */
 #app .studentLayout section.app-main:has(.target-profile-page) .step-indicator {
   display: flex !important;

src/views/exam/index.vue

@@ -259,13 +259,3 @@ function count(value){return value==="ALL"?exams.value.length:exams.value.filter
   }
 }
 </style>
-
-<style lang="scss">
-/* 页面画布：纯白，无渐变 */
-#app .studentLayout .app-main:has(.student-exams) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.student-exams) .student-exams {
-  line-height: 1.55 !important;
-}
-</style>

src/views/exam/result.vue

@@ -261,13 +261,3 @@ aside {
   }
 }
 </style>
-
-<style lang="scss">
-/* 页面画布：纯白，无渐变 */
-#app .studentLayout .app-main:has(.result-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.result-page) .result-page {
-  line-height: 1.55 !important;
-}
-</style>

src/views/exam/take.vue

@@ -384,13 +384,3 @@ function formatTime(v){return v?new Date(v).toLocaleString("zh-CN",{hour12:false
   }
 }
 </style>
-
-<style lang="scss">
-/* 页面画布：纯白，无渐变 */
-#app .studentLayout .app-main:has(.take-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.take-page) .take-page {
-  line-height: 1.55 !important;
-}
-</style>

src/views/foundation/new-product-survey.vue

@@ -1960,16 +1960,6 @@ function exportOutcome() {
   所有选择器均以 .new-product-value-page 为根，不影响其他页面。
 -->
 <style lang="scss">
-/* 页面画布：纯白，不使用任何底色渐变 */
-#app .studentLayout .app-main:has(.new-product-value-page) {
-  background: #ffffff !important;
-}
-
-/* 全局 shell 行高为 1.8，本页收紧为 1.55（选择器特异性对齐全局规则） */
-#app .studentLayout .app-main:has(.new-product-value-page) .new-product-value-page {
-  line-height: 1.55 !important;
-}
-
 /* ============================================================
  * 步骤导航重设计：按钮切换风（分段按钮 + 墨黑激活）
  * id 锚点 + !important 覆盖全局浅蓝胶囊与杂志风旧规则。

src/views/foundation/product-development-factors.vue

@@ -934,17 +934,6 @@ function exportOutcome() {
 </style>
 
 <style lang="scss">
-/* 页面画布：纯白，不使用任何底色渐变（scoped 无法触及祖先 app-main） */
-#app .studentLayout section.app-main:has(.product-factors) {
-  background: #ffffff !important;
-  background-image: none !important;
-}
-
-/* 全局 shell 行高 1.8，本页收紧为 1.55 */
-#app .studentLayout .app-main:has(.product-factors) .product-factors {
-  line-height: 1.55 !important;
-}
-
 /* ===== AI 侧栏样式已收敛进 TrainingAiSidebar 组件（墨黑极简），此处不再覆盖 ===== */
 
 /* ============================================================

src/views/foundation/product-development-process.vue

@@ -1359,17 +1359,6 @@ tr.is-incorrect .classification-feedback {
 </style>
 
 <style lang="scss">
-/* 页面画布：纯白，不使用任何底色渐变（scoped 无法触及祖先 app-main） */
-#app .studentLayout section.app-main:has(.product-process) {
-  background: #ffffff !important;
-  background-image: none !important;
-}
-
-/* 全局 shell 行高 1.8，本页收紧为 1.55 */
-#app .studentLayout .app-main:has(.product-process) .product-process {
-  line-height: 1.55 !important;
-}
-
 /* ===== AI 侧栏样式已收敛进 TrainingAiSidebar 组件（墨黑极简），此处不再覆盖 ===== */
 
 /* ============================================================

src/views/product/after-sales-service.vue

@@ -1156,14 +1156,6 @@ button:disabled {
 </style>
 
 <style lang="scss">
-/* ===== 画布白底 + 1.55 行高 ===== */
-#app .studentLayout .app-main:has(.after-sales-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.after-sales-page) .after-sales-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风（覆盖全局 !important 浅蓝胶囊） ===== */
 #app .studentLayout section.app-main:has(.after-sales-page) .step-indicator {
   display: flex !important;

src/views/product/differentiation.vue

@@ -1432,14 +1432,6 @@ async function handleValueCanvasUpload(event) {
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.product-positioning-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.product-positioning-page) .product-positioning-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.product-positioning-page) .step-indicator {
   display: flex !important;

src/views/product/hardware-cost.vue

@@ -1422,14 +1422,6 @@ onMounted(async () => {
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.hardware-cost-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.hardware-cost-page) .hardware-cost-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.hardware-cost-page) .step-indicator {
   display: flex !important;

src/views/product/market-opportunity-selection.vue

@@ -798,14 +798,6 @@ function exportOutcome() { const blob = new Blob([JSON.stringify({ taskName: tas
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.opportunity-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.opportunity-page) .opportunity-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.opportunity-page) .step-indicator {
   display: flex !important;

src/views/product/price.vue

@@ -2325,14 +2325,6 @@ onMounted(async () => {
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.price-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.price-page) .price-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.price-page) .step-indicator {
   display: flex !important;

src/views/product/requirements-doc.vue

@@ -1397,14 +1397,6 @@ function exportOutcome() { if (currentStep.value === 2) { exportStepTwoTable();
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.requirements-doc-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.requirements-doc-page) .requirements-doc-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.requirements-doc-page) .step-indicator {
   display: flex !important;

src/views/product/structure.vue

@@ -1148,14 +1148,6 @@ button:disabled {
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.architecture-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.architecture-page) .architecture-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.architecture-page) .step-indicator {
   display: flex !important;

src/views/student/index.vue

@@ -424,15 +424,12 @@ onBeforeUnmount(() => {
 
 <style lang="scss">
 /*
- * 学生首页贴边纯白（scoped 无法触及祖先，故放在非 scoped 块）：
- * 1) app-main 深蓝背景图/渐变 → 纯白，padding 清零；
- * 2) 外层 .index 的 10px margin 清零，内容贴边。
- * 选择器以 .student-home :has 为锚，不影响其他角色/页面。
+ * 学生首页贴边布局（scoped 无法触及祖先，故放在非 scoped 块）：
+ * 背景渐变由全局 student-training.scss 统一提供（.app-main:has(.student-home)）；
+ * 此处仅保留 padding 清零与外层 .index 的 margin 清零，使首页内容贴边。
  */
 #app .studentLayout section.app-main:has(.student-home) {
   padding: 0 !important;
-  background: #ffffff !important;
-  background-image: none !important;
 }
 
 #app .studentLayout .app-main:has(.student-home) .index {

src/views/test-report/index.vue

@@ -108,12 +108,4 @@ onMounted(async()=>{const res=await getCurrentExperimentReport(); report.value=r
 </style>
 
 <style lang="scss">
-/* 墨黑极简 · 纯白画布覆盖（scoped 触及不到祖先画布） */
-#app .studentLayout .app-main:has(.test-report) {
-  background: #ffffff !important;
-}
-
-#app .studentLayout .app-main:has(.test-report) .test-report {
-  line-height: 1.55 !important;
-}
 </style>

src/views/test/index.vue

@@ -405,6 +405,17 @@ onMounted(async () => { try { const result = await getTrainingTaskByKey(TASK_KEY
 
 .release-channel-toolbar {
   flex: 0 0 auto;
+  width: 320px;
+
+  :deep(.material-actions) {
+    display: grid;
+    grid-template-columns: 1fr 1fr;
+    gap: 8px;
+  }
+
+  :deep(.material-button) {
+    width: 100%;
+  }
 }
 
 /* ===== task-card：透明容器 ===== */
@@ -673,14 +684,6 @@ onMounted(async () => { try { const result = await getTrainingTaskByKey(TASK_KEY
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.release-channel-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.release-channel-page) .release-channel-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤条：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.release-channel-page) .step-tabs {
   display: flex !important;
@@ -811,7 +814,7 @@ onMounted(async () => { try { const result = await getTrainingTaskByKey(TASK_KEY
 }
 
 /* ===== 工具栏 el-button 换肤 ===== */
-.release-channel-page .release-channel-toolbar.material-button.el-button {
+.release-channel-page .release-channel-toolbar .material-button.el-button {
   display: inline-flex;
   align-items: center;
   justify-content: center;
@@ -829,18 +832,18 @@ onMounted(async () => { try { const result = await getTrainingTaskByKey(TASK_KEY
   font-weight: 600;
   transition: border-color 0.16s ease, background 0.16s ease, color 0.16s ease, box-shadow 0.16s ease;
 }
-.release-channel-page .release-channel-toolbar.material-button.el-button .el-icon {
+.release-channel-page .release-channel-toolbar .material-button.el-button .el-icon {
   font-size: 14px;
   color: inherit;
 }
-.release-channel-page .release-channel-toolbar.material-button.el-button:hover,
-.release-channel-page .release-channel-toolbar.material-button.el-button:focus {
+.release-channel-page .release-channel-toolbar .material-button.el-button:hover,
+.release-channel-page .release-channel-toolbar .material-button.el-button:focus {
   border-color: #1f2937;
   color: #1f2937;
   background: #f9fafb;
   box-shadow: 0 2px 6px rgba(17, 24, 39, 0.1);
 }
-.release-channel-page .release-channel-toolbar.material-button.el-button.is-loading {
+.release-channel-page .release-channel-toolbar .material-button.el-button.is-loading {
   border-color: #d1d5db;
   color: #374151;
   background: #ffffff;

src/views/test/promotion.vue

@@ -713,14 +713,6 @@ onMounted(async () => { try { const result = await getTrainingTaskByKey(TASK_KEY
 </style>
 
 <style lang="scss">
-/* ===== 画布 + 行高 ===== */
-#app .studentLayout .app-main:has(.promotion-page) {
-  background: #ffffff !important;
-}
-#app .studentLayout .app-main:has(.promotion-page) .promotion-page {
-  line-height: 1.55 !important;
-}
-
 /* ===== 步骤导航：按钮切换风 ===== */
 #app .studentLayout section.app-main:has(.promotion-page) .step-indicator {
   display: flex !important;

src/views/training/GenericTrainingPage.vue

@@ -3912,13 +3912,4 @@ function exportOutcome() {
 </style>
 
 <style lang="scss">
-/* 墨黑极简 · 纯白画布覆盖（scoped 触及不到祖先画布；用 id + 页面根类双类锚点压过全局浅蓝渐变） */
-#app .studentLayout .app-main:has(.student-training-page.student-training-shell),
-#app .teacherLayout .app-main:has(.student-training-page.student-training-shell) {
-  background: #ffffff !important;
-}
-
-#app .studentLayout .app-main:has(.student-training-page.student-training-shell) .student-training-page {
-  line-height: 1.55 !important;
-}
 </style>